Ferson byam



(No Model.)

s. T. J. BYAM. MANUFACTURE OF WATCH CASES. 4

No. 424.048. Patented Mar. 25, 1890.

UNITED STATES PATENT OFFICE.

SEWVALL THOMAS JEFFERSON BYAM, OF TRENTON, NEW JERSEY, ASSIGNOR TO THE TRENTON W'ATCH COMPANY, OF SAME PLACE.

MANUFACTURE OF WATCH-CASES.

SPECIFICATION forming part of Letters IPatent No. 424,048, dated March 25, 1890.

Application filed December 29, 1888\ Serial No. 294,949. (No model.)

To all whom it may concern.- I

Be it known that I, SEWALL THOMAS JEF- FERSON BYAM, of Trenton, in the county of Mercer, and in the State of New .Iersey,have invented certain new and useful Improvements in the Manufacture of Watch-Cases; and I do hereby declare that the following is a full, clear, and exact description thereof, referencebein g had to the accompanying drawings, in which- Figure 1 is a perspective View of the blank used for forming a case-back. Figs. 2 and 3 are like views of opposite sides of the same after having passed through the first operation. Figs. 4 and 5 are perspective views of said blank after having passed through the second swaging operation. Figs. 6 and 7 are like views of the same after having been operated upon by the trimming-dies, and Figs. 8 and 9 are perspective views of said blank after completion by the action of the final swaging-dies.

Letters of like name and kind refer to lik parts in each of the figures.

In the manufacture of watch-cases it has heretofore been customary to solder the projecting lip, which forms a thumb-piece, to or upon the edge of a case-back, whichoperation not only caused a considerable'expense, but was difiicult to perform so as to conceal the joint and solder.

The object of my invention is to remedy the defects named; and to such end such invention consists in the method employed for forming a case-back with the thumb-piece integral with and constituting a part of the same, substantially as and for the purpose hereinafter specified.

In the carrying of my invention into practice a disk A is cut from a sheet of metal by any desired means, and is then subjected to the action of dies which give to it a cupshaped form with an outward-projecting peripheral flange a, as shown in Figs. 2 and 3. The blank A is next subjected to the action of other dies, which at one side compress the flange a, so as to form in relief upon the outer face of the same a thumb=piece a, (shown in Figs. 4 and 5,) after which said blank is passed through other dies that remove nearly all of said flange and triin the surplus metal from around said thumb-piece, as seen in Fig. 6 and 7. The blank is now completed by subjecting it to the action of other dies which operate to give the edge a" upon the inner side a plane form, to extend the curve of the outer face inward to such edge, and to shape and define the thumb-piece a.

Each of the operations described, except the third, is necessary and usual in forming a case-back without a thumb-piece, so that the only expense involved in the production of the latter is the dies and time required for such operation. It will be obvious that the case-backthus constructed will be stronger and will present a better appearance than would be practicable if the thumb-piece was constructed separately and afterward attached thereto, and that the single additional operation necessary by my method will involve but a fraction of the expense heretofore required in forming, attaching, and finishing such part. It will also be obvious that the principle of operation will be the same whether a case-back, case-front, or glass-bezel are formed.

Having thus described my invention, what I claim is The method of forming a thumb-piece upon and integral with a case-back, which consists, first, in giving to a blank disk a cup shape with a peripheral flange, next in impressing upon such flange the form of the thumb-piece, next in removing the surplus metal from around the blank and thumb piece, and, finally, completing the combined case-back and thumb-piece by means of dies, substantially as and for thepurpose specified.

In testimony that I claim the foregoing I have hereunto set my hand this 26th day of November, 1888.

SEWALL THOMAS JEFFERSON BYAM.

Witnesses:

SAMUEL CADWALLADER, WILLIAM Y. JOHNSON. 

